Correlations between ADL in patients with SCI and caregiver burden, quality of life, and presenteeism in South Korea

The correlations between activities of daily living (ADL) among patients with spinal cord injury (SCI) and their caregivers’ burden, quality of life (QoL), and presenteeism was investigated. Participants included outpatients and inpatients with SCI at a rehabilitation center and their caregivers, recruited between March 2020 and April 2021. Eighty-seven valid responses were analysed using independent t-tests and Pearson’s correlations. There was a difference in caregiver burden according to patients’ ADL performance. QoL was negatively correlated with caregiver burden and presenteeism. Caregiver burden and presenteeism were positively correlated. Social support can improve caregivers’ QoL and reduce caregiver burden and presenteeism-induced work impairment.


Data collection
Prior to data collection, written consent for voluntary participation was obtained from the caregivers and patients from March 2020 to April 2021.
We used a structured questionnaire comprising questions about the ADL of patients with SCI and caregivers' general characteristics, caregiver burden, QoL, and presenteeism.The survey took 40-60 min to complete.The participants were informed that the questionnaire required personal information and that they could withdraw from the survey at any time without any disadvantages.To prevent response bias from the participants, one researcher read the questions aloud.The patients and their caregivers completed the survey in separate rooms.

Instruments
Caregiver burden Caregiver burden was measured using the Caregiver Burden Inventory 19 .The questionnaire consists of five subcategories: time-dependence burden (five items), developmental burden (four items), physical burden (four items), social burden (five items), and emotional burden (five items).Each item is rated on a five-point Likert scale (minimum 1 point, maximum 5 points).The scores range from 25 to 125 points, with higher scores indicating a higher level of caregiver burden.Cronbach's α in this study was 0.947.

ADL
ADL performance was measured using the Modified Barthel Index (MBI) 20 .The tool consists of 11 items rated from 0 to 5. Total scores range from 0 to 100, with 0 indicating total dependency and 100 indicating complete independence in ADL performance.An ADL score of 24 or lower corresponds to the first level of disability (highest dependence) in the disability rating criteria of the 2010 Korean Welfare for Persons with Disabilities Act enforcement regulations.Reliability of the MBI, indicated by Cronbach's alpha, was 0.944 in this study.

World Health Organization-QoL assessment
The Korean version of the Quality-of-Life Assessment from the World Health Organization (Geneva) comprises 26 facets across six domains: 24 facets focus on physical health (three facets), psychological health (five facets), level of independence (four facets), social relationship (three facets), environment (eight facets), and spirituality/ religion/personal beliefs (one facet), while two facets are related to general health and overall QoL.Cronbach's α was 0.859 in a previous study 21 and 0.901 in this study.

Presenteeism
Presenteeism was measured using 10 Likert-type questions from the 13-items Stanford Presenteeism Scale 22 .Responses were rated on a five-point scale ranging from 1 (always) to 5 (never).A higher score indicates a higher level of work impairment.Items 2, 5, 6, 8, and 10 are reverse-coded.For analysis, this study used a 100-point conversion method, (total score − 10)/40 × 100, as recommended by the developer of the original tool.Cronbach's α was 0.837 in a previous study 21 and 0.848 in this study.

Statistical analysis
Frequencies (%), means, and standard deviations of the following variables were calculated: ADL performance of patients with SCI and caregivers' general characteristics, caregiver burden, QoL, and presenteeism.To examine differences in caregiver burden based on the ADL performance of patients with SCI, independent t-tests were performed.To examine differences in caregiver burden based on the level of injury (cervical, thoracic, and lumbar), American Spinal Injury Association Impairment Scale (AIS; A, B, C, D), severity of injury (complete/ incomplete, tetraplegia/paraplegia), and post injury period of patients with SCI (3 year less, 3 to 10 years, over 10 years), ANOVA were performed.To examine correlations between the ADL performance of patients with SCI and caregivers' general characteristics, caregiver burden, QoL, and presenteeism, Pearson's correlation analysis was conducted.SPSS version 19.0 (IBM Corp., Armonk, NY, USA) was used for data analysis.The significance level was set at p < 0.05.

Ethics declarations
The Institutional Review Board at the National Rehabilitation Center approved this study (NRC-2020-02-012).All study participants had been invited to participate in the study and informed that participation is on their own choice and that they were free to withdraw at any time.

Characteristics of individuals with SCI and caregivers
The sex, age, body mass index (BMI), level of injury, AIS grade (A to D), severity of injury, MBI score, and postinjury period of people with spinal cord injury were described in Table 1.The mean (standard deviation) of ADL score for patients with SCI was 35.49(± 31.43).The general characteristics and related variables for caregivers were shown in Table 2.The mean (standard deviation) of caregiver burden were 64.97 (± 22.72).

Caregiver burden according to the characteristics of individuals with SCI
Caregiver burden according to the characteristics of individuals with SCI were shown in Table 3.There are no significant differences in level of injury, AIS grade, severity of injury (complete/incomplete, tetraplegia/ paraplegia), and post injury period (Table 3).In the comparative analysis of caregiver burden, QoL, and presenteeism in relation to patients' ADL scores, those who scored less than 24 points in ADL performance showed a significantly higher caregiver burden than those who scored 24 or more (p = 0.01).The results showed no significant differences in either QoL or presenteeism (Table 4).

Correlations between care-related variables (caregiver burden, QoL, presenteeism, and ADL)
An analysis of the correlations between care-related variables showed a highly significant negative correlation between QoL and caregiver burden (coefficient = −0.772,p < 0.01) and a moderately significant negative correlation between QoL and presenteeism (coefficient = −0.546,p < 0.01).Moreover, there was a moderately significant positive correlation between caregiver burden and presenteeism (coefficient = 0.581, p < 0.01; Table 5).

Discussion
Depending on the degree of motor and sensory impairment among patients with SCI, they may experience difficulties in life that make them entirely dependent on caregivers; conversely, they may be able to independently perform most ADL.As a result of these difficulties, patients with SCI also often experience psychological problems, such as anxiety and depression 23,24 .They can become dependent on others owing to physical disabilities, which may lead them to experience negative mental states such as shame, helplessness, low self-esteem, and depression.Owing to decreased contact with others, they gradually become isolated and lose their social roles 25 .The problem appears not only in patients with SCI but also in family caregivers.The families of individuals with SCI who require long-term care experience considerable caregiver burden in terms of time as well as financial,

Table 1 .
Characteristics of individuals with SCI (N = 87).MBI modified Barthel index, ADL activities of daily living, AIS American Spinal Injury Association Impairment Scale.

Table 2 .
General characteristics and related variables for caregivers (N = 87).QoL quality of life, SD standard deviation.

Table 3 .
Caregiver burden according to characteristics of individuals with SCI (N = 87).AIS American Spinal Injury Association Impairment Scale.

Table 4 .
Differences in presenteeism, caregiver burden, and QoL according to ADL scores.ADL activities of daily living, QoL quality of life.

Table 5 .
Relationships among care-related factors.ADL activities of daily living, QoL quality of life.*p < 0.01.